Three-Dimensional Shaping Apparatus And Method Of Manufacturing Three-Dimensional Shaping Object

ABSTRACT

A three-dimensional shaping apparatus includes a plasticizing portion plasticizing a material to generate a shaping material, a nozzle having a discharge port discharging the shaping material toward a table, a movement mechanism changing a relative position between the nozzle and the table, a discharge control mechanism provided in a flow path which connects the plasticizing portion to the nozzle and controlling a discharge amount of the shaping material from the nozzle, and a control portion controlling the plasticizing portion, the movement mechanism, and the discharge control mechanism to shape the three-dimensional shaping object. The control portion controls the discharge control mechanism so that when a relative movement speed between the nozzle and the table is a first speed, the discharge amount of the shaping material is set to a first discharge amount, and when the relative movement speed between the nozzle and the table is a second speed which is slower than the first speed, the discharge amount of the shaping material is set to a second discharge amount which is smaller than the first discharge amount.

This application is a divisional of U.S. patent application Ser. No.17/167,516 filed on Feb. 4, 2021, which is a divisional of U.S. patentapplication Ser. No. 16/697,300 filed on Nov. 27, 2019, now U.S. Pat.No. 11,077,619 issued on Aug. 3, 2021, which is based on, and claimspriority from, JP Application Serial Number 2018-221813, filed Nov. 28,2018, the disclosures of which are hereby incorporated by referenceherein in their entireties.

BACKGROUND 1. Technical Field

The present disclosure relates to a three-dimensional shaping apparatusand a method of manufacturing the three-dimensional shaping object.

2. Related Art

JP-A-2006-192710 discloses a technology in which a thermoplasticmaterial heated and melted by a preheater is extruded from an extrusionnozzle which scans in accordance with preset shape data to a specificarea on a base and the further-melted material is stacked on the curedmaterial on the base to shape a three-dimensional object.

When the extrusion nozzle is moved according to the shape data as in thetechnology described in JP-A-2006-192710, a movement speed of the nozzlemay be reduced depending on a shaping location such as a corner of ashaping object. When an amount of a material discharged from the nozzleis constant, reducing the movement speed of the nozzle may cause thedischarge amount of the material to be excessive, which may lowershaping precision.

SUMMARY

An advantage of some aspects of the present disclosure is to improve theshaping precision of the three-dimensional shaping object.

According to a first aspect of the present disclosure, athree-dimensional shaping apparatus that shapes a three-dimensionalshaping object is provided. The three-dimensional shaping apparatusincludes a plasticizing portion plasticizing a material to generate ashaping material, a nozzle having a discharge port discharging theshaping material toward a table, a movement mechanism changing arelative position between the nozzle and the table, a discharge controlmechanism provided in a flow path which connects the plasticizingportion to the nozzle and controlling a discharge amount of the shapingmaterial from the nozzle, and a control portion controlling theplasticizing portion, the movement mechanism, and the discharge controlmechanism to shape the three-dimensional shaping object, in which thecontrol portion controls the discharge control mechanism so that when arelative movement speed between the nozzle and the table is a firstspeed, the discharge amount of the shaping material is set to a firstdischarge amount, and when the relative movement speed between thenozzle and the table is a second speed which is slower than the firstspeed, the discharge amount of the shaping material is set to a seconddischarge amount which is smaller than the first discharge amount.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory view showing a schematic configuration of athree-dimensional shaping apparatus.

FIG. 2 is a view schematically showing a configuration of a dischargecontrol mechanism and a suction portion.

FIG. 3 is a schematic perspective view showing a configuration on alower surface side of a flat screw.

FIG. 4 is a schematic plan view showing an upper surface side of a screwfacing portion.

FIG. 5 is a view schematically showing an aspect of how athree-dimensional shaping object is shaped.

FIG. 6 is a flowchart showing a method of manufacturing thethree-dimensional shaping object.

FIG. 7 is a view schematically showing a part of the three-dimensionalshaping object represented by shaping data.

FIG. 8 is a view showing a relationship between a movement speed of anozzle and a discharge amount of a shaping material.

DESCRIPTION OF EXEMPLARY EMBODIMENTS A. First Embodiment

FIG. 1 is an explanatory view showing a schematic configuration of athree-dimensional shaping apparatus 100 in a first embodiment. In FIG.1, arrows along X, Y, and Z directions orthogonal to one another arerepresented. The X direction and the Y direction are directions along ahorizontal direction, and the Z direction is a vertically upwarddirection. In the other figures, arrows along the X, Y, and Z directionsare appropriately represented. The X, Y, Z directions in FIG. 1 and theX, Y, and Z directions in the other figures represent the samedirection.

The three-dimensional shaping apparatus 100 includes a control portion101, a shaping portion 110 which generates and discharges a shapingmaterial, a table 210 for shaping a base of a three-dimensional shapingobject, and a movement mechanism 230 which controls a discharge positionof the shaping material.

The control portion 101 controls the entire operation of thethree-dimensional shaping apparatus 100 to perform shaping processingwhich shapes the three-dimensional shaping object. The control portion101 is constituted with a computer including one or a plurality ofprocessors and a main storage apparatus. The control portion 101performs various functions by the processor executing a program read inthe main storage apparatus. Further, a part of the functions of thecontrol portion 101 may be realized by a hardware circuit. In theshaping processing performed by the control portion 101, the shapingportion 110 and the movement mechanism 230 are controlled in accordancewith shaping data of the three-dimensional shaping object.

The shaping portion 110 discharges the melted paste-like shapingmaterial to a target position on the table 210 under the control of thecontrol portion 101. The shaping portion 110 includes a material supplyportion 20 which is a source of a material MR before the material MR isconverted to the shaping material, a plasticizing portion 30 convertingthe material MR to the shaping material, a nozzle 61 having a dischargeport 62 which discharges the shaping material toward the table, adischarge control mechanism 70 controlling a discharge amount of theshaping material from the nozzle 61, and a suction portion 75 suctioningand temporarily reserving the shaping material.

The material supply portion 20 supplies the plasticizing portion 30 withthe material MR to generate the shaping material. The material supplyportion 20 is constituted with, for example, a hopper which accommodatesthe material MR. The material supply portion 20 is connected to theplasticizing portion 30 via a communication passage 22. The material MRis introduced into the material supply portion 20 in a form of, forexample, a pellet or a powder, or the like. Details of the material MRwill be described later.

The plasticizing portion 30 plasticizes at least a part of the materialMR supplied from the material supply portion 20 to generate thepaste-like shaping material exhibiting fluidity, and guides the shapingmaterial to the nozzle 61. The plasticizing portion 30 has a screw case31, a drive motor 32, a flat screw 40 and a screw facing portion 50. Theflat screw 40 is also called a “scroll”. The screw facing portion 50 isalso called a “barrel”. The plasticizing portion 30 may plasticize allof the material MR, or may plasticize a part of the material MRcomponents, for example, when the material MR includes a plurality ofcomponents.

The flat screw 40 has a substantially cylindrical shape whose heightalong a central axis RX thereof is smaller than a diameter thereof. Inthe present embodiment, the flat screw 40 is disposed such that thecentral axis RX is parallel to the Z direction.

The flat screw 40 is housed in the screw case 31. An upper surface 47side of the flat screw 40 is connected to the drive motor 32, and theflat screw 40 rotates around the central axis RX in the screw case 31 bya rotational drive force generated by the drive motor 32. The drivemotor 32 drives under the control of the control portion 101.

A groove portion 42 is formed on a lower surface 48 of the flat screw40. The communication passage 22 of the material supply portion 20described above communicates with the groove portion 42 from a sidesurface of the flat screw 40.

The lower surface 48 of the flat screw 40 faces an upper surface 52 ofthe screw facing portion 50. A space is formed between the grooveportion 42 of the lower surface 48 of the flat screw 40 and the uppersurface 52 of the screw facing portion 50. The material MR is suppliedfrom the material supply portion 20 to the space. Specificconfigurations of the flat screw 40 and the groove portion 42 will bedescribed later.

In the screw facing portion 50, a heater 58 for heating the material MRis embedded. The material MR supplied to the groove portion 42 of theflat screw 40 flows along the groove portion 42 by rotation of the flatscrew 40 while being melted in the groove portion 42 and is guided to acenter portion 46 of the flat screw 40 as the shaping material. Thepaste-like shaping material flowing into the center portion 46 issupplied to the nozzle 61 through a communication hole 56 provided at acenter of the screw facing portion 50. In the shaping material, alltypes of substances constituting the shaping material may not have to bemelted. The shaping material may be converted into a state havingfluidity as a whole by melting at least one type of substance among thesubstances constituting the shaping material.

The nozzle 61 is connected to the communication hole 56 of the screwfacing portion 50 through a flow path 65 connecting the plasticizingportion 30 and the nozzle 61. The nozzle 61 discharges the shapingmaterial generated in the plasticizing portion 30 from the dischargeport 62 at a tip thereof toward the table 210. In the presentembodiment, the flow path 65 extends along the Z direction, and the flowpath 65 and the nozzle 61 are disposed along the Z direction.

The table 210 is disposed at a position facing the discharge port 62 ofthe nozzle 61. In the present embodiment, an upper surface 211 of thetable 210 facing the discharge port 62 of the nozzle 61 is disposedhorizontally, that is, parallel to the X and Y directions.

The movement mechanism 230 is configured to be able to change a relativeposition of the table 210 and the nozzle 61. In the present embodiment,a position of the nozzle 61 is fixed, and the movement mechanism 230moves the table 210. The movement mechanism 230 is constituted with athree-axis positioner which moves the table 210 in the three directionsof the X, Y, and Z directions by drive force of three motors. Themovement mechanism 230 changes relative positional relationship betweenthe nozzle 61 and the table 210 under the control of the control portion101.

In another embodiment, a configuration may be adopted in which insteadof moving the table 210 by the movement mechanism 230, the movementmechanism 230 moves the nozzle 61 relative to the table 210 with aposition of the table 210 fixed. Further, a configuration in which thetable 210 is moved in the Z direction by the movement mechanism 230 andthe nozzle 61 is moved in the X and Y directions, or a configuration inwhich the table 210 is moved in the X and Y directions by the movementmechanism 230 and the nozzle 61 is moved in the Z direction, may beadopted. Even in these configurations, the relative positionalrelationship between the nozzle 61 and the table 210 can be changed.

In the following, “movement of the nozzle 61” or “scanning of the nozzle61” means change in a relative position of the nozzle 61 with respect tothe table 210 unless otherwise specified. Further, when “movement speedof the nozzle 61” is mentioned, it means a relative speed of the nozzle61 with respect to the table 210.

FIG. 2 is a view schematically showing a configuration of the dischargecontrol mechanism 70 and the suction portion 75. In the presentembodiment, the discharge control mechanism 70 includes a butterflyvalve 72 which changes an opening degree of the flow path 65 by rotationthereof in the flow path 65. The butterfly valve 72 includes a driveshaft 73 which is a shaft-like member extending in one direction, and avalve portion 73 v which rotates with the rotation of the drive shaft73. The drive shaft 73 is attached at the flow path 65 so as to cross aflow direction of the shaping material. In the present embodiment, thedrive shaft 73 is disposed parallel to the Y direction so as to crossthe flow path 65 perpendicularly. The drive shaft 73 is rotatable abouta central axis 73 x thereof.

The valve portion 73 v is a plate-like portion which rotates in the flowpath 65. In the first embodiment, the valve portion 73 v is formed byprocessing a portion of the drive shaft 73 disposed in the flow path 65into a plate shape. The shape when the valve portion 73 v is viewed in adirection perpendicular to a plate surface thereof substantially matchesan opening shape of the flow path 65 at a portion in which the valveportion 73 v is disposed.

A state in which a plate surface of the valve portion 73 v follows alongthe flow direction of the shaping material in the flow path 65, as shownby a solid line in FIG. 2, is the state in which the flow path 65 isopen. In the state, inflow of the shaping material is allowed from thebutterfly valve 72 to the nozzle 61 side. As illustrated by a brokenline in FIG. 2, a state in which the plate surface of the valve portion73 v is perpendicular to the flow direction of the shaping material inthe flow path 65 is the state in which the flow path 65 is closed. Inthe state, the inflow of the shaping material from the butterfly valve72 to the nozzle 61 side is blocked, and the discharge of shapingmaterial from the discharge port 62 of the nozzle 61 is stopped. Thecontrol portion 101 can adjust a flow rate of shaping material flowingfrom the plasticizing portion 30 to the nozzle 61, that is, the flowrate of the shaping material discharged from the nozzle 61, bycontrolling a rotation angle of the butterfly valve 72.

A first drive portion 74 shown in FIG. 1 is constituted with, forexample, a stepping motor. The first drive portion 74 controls thedischarge amount of the shaping material from the nozzle 61 by rotatingthe drive shaft 73 and adjusting a rotation angle of the valve portion73 v under the control of the control portion 101. In the presentembodiment, the control portion 101 controls the discharge controlmechanism 70 so that when the movement speed of the nozzle 61 is a firstspeed, the discharge amount of the shaping material is set to a firstdischarge amount, and when the movement speed of the nozzle 61 is asecond speed which is slower than the first speed, the discharge amountof the shaping material is set to a second discharge amount which issmaller than the first discharge amount. Further, in the presentembodiment, the control portion 101 controls the discharge controlmechanism 70 according to the movement speed of the nozzle 61 to controlthe discharge amount so that the discharge amount of the shapingmaterial per unit volume in the three-dimensional shaping object isconstant before and after the movement speed of the nozzle 61 changes.

The suction portion 75 is connected to the flow path 65 between thedischarge control mechanism 70 and the discharge port 62. The suctionportion 75 sucks and temporarily stores the shaping material in the flowpath 65. In the present embodiment, the suction portion 75 isconstituted with a plunger including a sub flow path 77 connected to theflow path 65 and a valve body 78 moving in the sub flow path 77. Thesuction portion 75 generates a negative pressure by moving the valvebody 78 in the sub flow path 77 and sucks the shaping material. The subflow path 77 extends linearly toward a side direction of the flow path65. The valve body 78 is constituted with a rod-like member extendingalong the sub flow path 77, and is disposed to be reciprocally movablein the sub flow path 77.

A second drive portion 76 driving the suction portion 75 illustrated inFIG. 1 changes a position of the valve body 78 in the sub flow path 77under the control of the control portion 101. The second drive portion76 is constituted with, for example, a stepping motor, and arack-and-pinion mechanism or a ball screw mechanism which converts arotational force of the stepping motor into translational motion of thevalve body 78.

In the present embodiment, as described above, the suction portion 75 isconnected between the discharge control mechanism 70 and the dischargeport 62. That is, a distance from the suction portion 75 to the nozzle61 is shorter than a distance from the discharge control mechanism 70 tothe nozzle 61. Therefore, in the present embodiment, responsiveness ofthe suction portion 75 regarding discharge or stop of the shapingmaterial is superior to responsiveness of the discharge controlmechanism 70.

When the shaping material is discharged from the nozzle 61, as shown inFIG. 2, the second drive portion 76 positions the valve body 78 at aposition in which an end thereof faces the flow path 65 and the inflowof the shaping material to the sub flow path 77 is blocked. When thedischarge of the shaping material from the nozzle 61 is stopped, thesecond drive portion 76 moves the valve body 78 away from the flow path65 to a position illustrated by a broken line in FIG. 2. As a result, avolume of a space communicating with the flow path 65 in the sub flowpath 77 is increased, the shaping material is drawn from the flow path65 to the sub flow path 77, and the shaping material discharged from thenozzle 61 is trimmed.

In the present embodiment, for example, when controlling the dischargecontrol mechanism 70 to stop the discharge of the shaping material fromthe nozzle 61, the control portion 101 causes the suction portion 75 toperform suction of the shaping material. Further, in the presentembodiment, for example, when starting or resuming the discharge of theshaping material from the nozzle 61, the control portion 101 starts themovement of the nozzle 61 after transmitting part of the shapingmaterial reserved in the suction portion 75 from the suction portion 75to the flow path 65, and controls the discharge control mechanism tostart supplying the shaping material from the plasticizing portion 30 tothe nozzle 61 and to send the remaining shaping material reserved in thesuction portion 75 from the suction portion 75 to the flow path 65.Control contents of the control portion 101 will be described in detaillater.

FIG. 3 is a schematic perspective view showing a configuration of thelower surface 48 side of the flat screw 40. In FIG. 3, a position of thecentral axis RX of the flat screw 40 is illustrated by an alternate longand short dash line. As described with reference to FIG. 1, a grooveportion 42 is provided on the lower surface 48 of the flat screw 40facing the screw facing portion 50. Hereinafter, the lower surface 48 isalso referred to as the “grooved surface 48”.

The center portion 46 of the grooved surface 48 of the flat screw 40 isconstituted with a recess portion to which one end of the groove portion42 is connected. The center portion 46 faces the communication hole 56of the screw facing portion 50 as shown in FIG. 1. In the firstembodiment, the center portion 46 intersects with the central axis RX.

The groove portion 42 of the flat screw 40 constitutes a so-calledscroll groove. The groove portion 42 extends in a spiral shape so as todraw an arc from the center portion 46 to an outer circumference of theflat screw 40. The groove portion 42 may be configured to extendhelically. The grooved surface 48 is provided with a projection stripportion 43 which constitutes a side wall portion of the groove portion42 and extends along each groove portion 42.

The groove portion 42 is continuous to a material inlet 44 formed on aside of the flat screw 40. The material inlet 44 is a part whichreceives the material MR supplied via the communication passage 22 ofthe material supply portion 20.

An example of a flat screw 40 having the three groove portions 42 andthe three projection strip portions 43 is shown in FIG. 3. The number ofthe groove portions 42 and the projection strip portions 43 provided inthe flat screw 40 is not limited to three. Only the one groove portion42 may be provided in the flat screw 40, or a plurality of the grooveportions 42 such as two or more may be provided. Further, an arbitrarynumber of the projection strip portions 43 may be provided in accordancewith the number of the groove portions 42.

An example of the flat screw 40 in which the material inlet 44 is formedat three places is shown in FIG. 3. The number of the material inlets 44provided in the flat screw 40 is not limited to three. In the flat screw40, the material inlet 44 may be provided at only one place, or may beprovided at a plurality of places such as two or more places.

FIG. 4 is a schematic plan view showing the upper surface 52 side of thescrew facing portion 50. The upper surface 52 of the screw facingportion 50 faces the grooved surface 48 of the flat screw 40 asdescribed above. Hereinafter, the upper surface 52 is also referred toas the “screw facing surface 52”. At a center of the screw facingsurface 52, the communication hole 56 described above for supplying theshaping material to the nozzle 61 is formed.

In the screw facing surface 52, a plurality of guide grooves 54 whichare connected to the communication hole 56 and spirally extending fromthe communication hole 56 toward an outer circumference of the screwfacing surface 52, are formed. The plurality of guide grooves 54 have afunction of guiding the shaping material flowing into the center portion46 of the flat screw 40 to the communication hole 56. As described withreference to FIG. 1, the screw facing portion 50 has the heater 58embedded therein. Melting of the material MR in the plasticizing portion30 is realized by heating by the heater 58 and the rotation of the flatscrew 40.

Please refer to FIG. 1 and FIG. 2. As the flat screw 40 rotates, thematerial MR supplied from the material inlet 44 is guided to the grooveportion 42 and moved toward the center portion 46 while being heated inthe groove portion 42. The material MR melts and becomes more fluid asthe material MR approaches the center portion 46, and is converted intothe shaping material. The shaping material collected in the centerportion 46 flows out from the communication hole 56 by an internalpressure generated in the center portion 46, is guided by the flow path65 of the nozzle 61, and is discharged from the discharge port 62.

FIG. 5 is a view schematically showing how the three-dimensional shapingobject is shaped by the three-dimensional shaping apparatus 100. In thethree-dimensional shaping apparatus 100, as described above, the shapingmaterial MM is generated in the plasticizing portion 30. Then, while thenozzle 61 is moved in a direction along the upper surface 211 of thetable 210 by the movement mechanism 230, a shaping material MM isdischarged from the nozzle 61 toward the upper surface 211 of the table210.

Here, a layer formed of the shaping material MM discharged by theshaping processing when the nozzle 61 is at a same height position withrespect to the upper surface 211 of the table 210 is referred to as a“shaping layer ML”. The control portion 101 shapes the three-dimensionalshaping object by moving the position of the nozzle 61 in the Zdirection and further stacking the shaping material MM by the nextshaping processing on the shaping layer ML formed by the previousshaping processing. That is, the three-dimensional shaping apparatus 100manufactures the three-dimensional shaping object by stacking theshaping layer ML in multiple layers.

When the shaping layer ML is formed, it is desirable that a followinggap G is maintained between the discharge port 62 at the tip of thenozzle 61 and a planned portion MLt on which the shaping material MMdischarged from nozzle 61 is to be stacked, at a vicinity of a positionimmediately below the nozzle 61. When the shaping material MM isdischarged on the shaping layer ML, the planned portion MLt, on whichthe shaping material MM is to be discharged, is an upper surface of theshaping layer ML located below the nozzle 61.

It is preferable that a size of the gap G is equal to or greater than ahole diameter Dn at the discharge port 62 of the nozzle 61, and morepreferably equal to or greater than 1.1 times the hole diameter Dn. Inthis way, the shaping material MM discharged from the discharge port 62of the nozzle 61 is stacked in a free state in which the shapingmaterial MM is not pressed against the planned portion MLt. As a result,a cross-sectional shape of the shaping material MM discharged from thenozzle 61 can be suppressed from being broken, and surface roughness ofthe three-dimensional shaping object can be reduced. Further, in aconfiguration in which a heater is provided around the nozzle 61,overheating of the shaping material MM by the heater can be prevented byforming the gap G, and discoloration and deterioration by theoverheating of the shaping material MM after stacking can be suppressed.On the other hand, it is preferable that the size of the gap G is 1.5times or less than the hole diameter Dn, and particularly preferablethat the size is 1.3 times or less. As a result, positional deviation ofthe discharge position of the shaping material MM with respect to theplanned portion MLt and a decrease in adhesion between the shapinglayers ML are suppressed.

FIG. 6 is a flowchart showing a method of manufacturing thethree-dimensional shaping object. FIG. 7 is a view schematically showinga part of a three-dimensional shaping object OB. FIG. 8 is a diagramshowing a relationship between the movement speed of the nozzle 61 andthe discharge amount of the shaping material.

A method of manufacturing shown in FIG. 6 is realized by executing ashaping program read into the main storage apparatus by the controlportion 101 of the three-dimensional shaping apparatus 100. Theflowchart shown in FIG. 6 is a flowchart corresponding to a process fromthe start of the discharge of the shaping material from the nozzle 61 tothe stop of the discharge, and in practice, the entirety of thethree-dimensional shaping object is shaped by repeatedly performing theflowchart shown in FIG. 6. When the method of manufacturing is started,it is assumed that the butterfly valve 72 of the discharge controlmechanism 70 is in a closed state in advance and the shaping material issucked and reserved in the suction portion 75 from the flow path 65.Such a state can be generated by setting the discharge control mechanism70 to a closed state while the nozzle 61 is moved to a predeterminedplace to discard the shaping material in the flow path 65, anddischarging and tailing the shaping material in the flow path 65 by thesuction portion 75. Further, even when a series of processing describedbelow is completed, the above state is obtained.

When starting or resuming the discharge of the shaping material, thecontrol portion 101 first controls the suction portion 75 in a step S10to extrude a part of the shaping material reserved in the suctionportion 75 and discharge the shaping material from the nozzle 61, andwaits for a predetermined period of time in a step S20. In FIG. 7,extrusion of the shaping material is performed at a position indicatedas “START”. A waiting period in the step S20 is a period required forthe shaping material extruded from the suction portion 75 to land on thetable 210 or the shaping-completed shaping layer ML, and is apredetermined period. The table 210 and the shaping-completed shapinglayer are hereinafter referred to as the “table 210 or the like”. Theamount of the shaping material extruded from the suction portion 75 inthe step S10 is, for example, 50% by mass of the shaping materialreserved in the suction portion 75. The amount is predeterminedaccording to thickness of the shaping material when the shaping materialis stacked on the table 210 or the like and the gap G described above.The thickness of the discharged shaping material is also referred to asa “line width”. The control portion 101 can adjust the amount ofextrusion of the material by controlling the second drive portion 76 tocontrol the amount of movement of the valve body 78.

After the waiting in the step S20 is completed, in a step S30, thecontrol portion 101 starts the movement of the nozzle 61 in accordancewith shaping data. The shaping data includes, for example, informationindicating movement path of the nozzle 61 and the movement speed of thenozzle 61. Simultaneously with the start of the movement of the nozzle61 or immediately after the start of the movement of the nozzle 61, thecontrol portion 101 controls the discharge control mechanism 70 toincrease the opening degree of the flow path 65 in a step S40, therebystarting the supply of the shaping material from the plasticizingportion 30 to the nozzle 61 and extruding the remaining shaping materialreserved in the suction portion 75 from the suction portion 75 to sendthe shaping material to the flow path 65. As a result, the dischargeamount of the shaping material from the nozzle 61 increases more thanthe discharge amount in the step S10. In the present embodiment, a firsttiming to start supplying the shaping material from the plasticizingportion 30 to the nozzle 61 and a second timing to extrude the shapingmaterial from the suction portion 75 are simultaneous. However, thesetimings may be shifted. That is, the first timing may be earlier thanthe second timing, or the first timing may be later than the secondtiming. Immediately after the movement of the nozzle 61 is started inthe step S30, the movement speed of the nozzle 61 is a relatively slowspeed, and after the step S40, the movement speed of the nozzle 61 is arelatively high speed in a linear part of the three-dimensional shapingobject OB. The movement speed of the nozzle 61 is slow at a corner ofthe three-dimensional shaping object OB.

In the step S40, the control portion 101 controls the discharge amountof the shaping material by adjusting the rotation angle of the butterflyvalve 72 according to the movement speed of the nozzle 61. In thepresent embodiment, as shown in FIG. 8, the control portion 101 controlsthe rotation angle of the butterfly valve 72 so that the dischargeamount of the shaping material from the nozzle 61 increases as themovement speed of the nozzle 61 increases. Therefore, if the dischargeamount at different movement speeds is compared, when the movement speedof the nozzle 61 is the first speed, the discharge amount of the shapingmaterial is set to the first discharge amount, and when the movementspeed of the nozzle 61 is the second speed which is slower than thefirst speed, the discharge amount of the shaping material is set to thesecond discharge amount which is smaller than the first dischargeamount. In the present embodiment, when the “discharge amount of theshaping material” is simply mentioned, the term refers to the flow rateof the shaping material discharged from the nozzle 61 and to the amountof shaping material discharged from the nozzle 61 per unit time. Themovement speed of the nozzle 61 can be specified by acquiring a valuespecified by the shaping data from the shaping data. In anotherembodiment, the movement mechanism 230 may be provided with a rotaryencoder, a speed sensor, or an acceleration sensor to measure themovement speed of the nozzle 61.

In a step S50, the control portion 101 determines whether or not acurrent position of the nozzle 61 is at a vicinity of an end of themovement path of the nozzle 61 represented by the shaping data. The“vicinity of the end of the movement path” will be described later. Whenit is determined that the position of the nozzle 61 is not at thevicinity of the end of the movement path of the nozzle 61, the controlportion 101 specifies the movement speed of the nozzle 61 in a step S60,and according to the specified movement speed, adjusts the rotationangle of the butterfly valve 72 to control the discharge amount of theshaping material in a step S70.

In the steps S40 and S70, the control portion 101 controls the dischargeamount so that the discharge amount of the shaping material per unitvolume in the three-dimensional shaping object is constant before andafter the movement speed of the nozzle 61 changes. That is, in thepresent embodiment, for example, in FIG. 8, the control portion 101controls the discharge control mechanism 70 to control the dischargeamount so that a line width of the shaping material discharged to thetable 210 or the like does not change at fixed distances in the partindicated as “Slow” and the part indicated as “Fast” which havedifferent movement speeds of the nozzle 61. “The discharge amount of theshaping material per unit volume in the three-dimensional shaping objectis constant” means that the amount of the shaping material dischargedper same volume of the three-dimensional shaping object is the same. Thedischarge amount of the shaping material per unit volume in thethree-dimensional shaping object may not be completely constant beforeand after the movement speed of the nozzle 61 changes, for example, inthe range of ±10%, or preferably, in the range of ±5%.

When it is determined that the position of the nozzle 61 is at thevicinity of the end of the movement path of the nozzle 61 in the stepS50, the control portion 101 controls the discharge control mechanism 70in a step S80 to close the butterfly valve 72 and stop the discharge ofthe shaping material. Then, after the butterfly valve 72 is closed, in astep S90, the control portion 101 stops the movement of the nozzle 61and controls the suction portion 75 to suck the shaping material in theflow path 65 into the suction portion 75. The “vicinity of the end ofthe movement path” is a position which is traced back from the end ofthe movement path up to a predetermined distance along the path. Thedistance to be traced back is determined such that the amount of theshaping material discharged from the nozzle 61 from a time at which thebutterfly valve 72 is closed in the step S80 until the shaping materialis sucked by the suction portion 75 in the step S90 is determined byexperiment or calculation in advance and the shaping in the distance ispossible by the amount.

The control portion 101 manufactures the entire three-dimensionalshaping object by performing the method of manufacturing thethree-dimensional shaping object described above for all the movementpaths recorded in the shaping data.

In the three-dimensional shaping apparatus 100 of the present embodimentdescribed above, the discharge control mechanism 70 is controlledaccording to the movement speed of the nozzle 61 so that when themovement speed of the nozzle 61 is the first speed, the discharge amountof the shaping material is set to the first discharge amount, and whenthe movement speed of the nozzle 61 is the second speed which is slowerthan the first speed, the discharge amount of the shaping material isset to the second discharge amount which is smaller than the firstdischarge amount. Therefore, it is possible to suppress a change in theline width of the shaping material stacked on the table 210 or the likein a part in which the movement speed of the nozzle 61 changes, such asan end or a corner of the three-dimensional shaping object. Therefore,the shaping precision of the three-dimensional shaping object can beimproved.

Further, in the present embodiment, the discharge amount is controlledso that the discharge amount of the shaping material per unit volume inthe three-dimensional shaping object is constant before and after themovement speed of the nozzle 61 changes. Therefore, the shapingprecision of the three-dimensional shaping object can be furtherimproved.

Further, in the present embodiment, the butterfly valve 72 is controlledto control the discharge amount of the shaping material. Therefore, thedischarge amount of the shaping material can be adjusted by a simpleconfiguration.

Further, in the present embodiment, when the discharge of the shapingmaterial is stopped, the shaping material is sucked by the suctionportion 75, so that it is possible to suppress the trailing of theshaping material from the nozzle 61.

Further, in the present embodiment, when the discharge of the shapingmaterial from the nozzle 61 is started or resumed, the movement of thenozzle 61 is started after the suction portion 75 sends the part of theshaping material reserved in the suction portion 75 to the flow path 65and the part of the shaping material is discharged from the nozzle 61,and the discharge control mechanism 70 is controlled to start supplyingthe shaping material from the plasticizing portion 30 to the nozzle 61and the remaining shaping material reserved in the suction portion 75 issent from the suction portion 75 to the flow path 65. Therefore, it ispossible to discharge the shaping material using the highly responsivesuction portion 75 so as to compensate for the responsiveness of thedischarge control mechanism 70. Therefore, the shaping speed of thethree-dimensional shaping object can be improved.

Further, in the present embodiment, when it is determined that theposition of the nozzle 61 is at the vicinity of the end of the path fordischarging the shaping material, it is determined that the discharge ofthe shaping material from the nozzle 61 is stopped. Therefore, even inthe present embodiment in which the responsiveness of the dischargecontrol mechanism 70 is low, it is possible to stop the discharge of theshaping material with good timing. Therefore, the shaping precision ofthe three-dimensional shaping object can be improved.

Further, in the present embodiment, since the flat screw 40 is adoptedin the plasticizing portion 30, it is possible to miniaturize thethree-dimensional shaping apparatus 100.

Here, the material of the three-dimensional shaping object used in thethree-dimensional shaping apparatus 100 described above will bedescribed. In the three-dimensional shaping apparatus 100, thethree-dimensional shaping object can be shaped, for example, withvarious materials such as a material having thermoplasticity, a metalmaterial, and a ceramic material as a main material. Here, the “mainmaterial” means a main material which forms a shape of thethree-dimensional shaping object, and means a material which accountsfor a content of 50% by weight or more in the three-dimensional shapingobject. The shaping material described above includes one in which themain material is melted alone, and one in which a part of the componentscontained together with the main material is melted and made into apaste shape.

When a material having thermoplasticity is used as the main material,the shaping material is generated in the plasticizing portion 30 by thematerial being plasticized. A “plasticization” means that heat isapplied to the material having thermoplasticity to melt the material.

As the material having thermoplasticity, for example, the followingthermoplastic resin material can be used.

Examples of Thermoplastic Resin Materials

General purpose engineering plastics such as polypropylene resin (PP),polyethylene resin (PE), polyacetal resin (POM), polyvinyl chlorideresin (PVC), polyamide resin (PA), acrylonitrile butadiene styrene resin(ABS), polylactic acid resin (PLA), polyphenylene sulfide resin (PPS),polyetheretherketone (PEEK), polycarbonate (PC), modified polyphenyleneether, polybutylene terephthalate, and polyethylene terephthalate, orengineering plastics such as polysulfone, polyether sulfone,polyphenylene sulfide, polyarylate, polyimide, polyamide imide,polyether imide, and polyether ether ketone

In the material having thermoplasticity, additives such as a wax, aflame retardant, an antioxidant, and a heat stabilizer may be mixed witha pigment, a metal, a ceramic, or the like. The thermoplastic materialis plasticized and converted to a melted state in the plasticizingportion 30 by the rotation of the flat screw 40 and the heating of theheater 58. The shaping material generated by the melting of thethermoplastic material is discharged from the nozzle 61 and then curedby a decrease in temperature.

It is desirable that the material having thermoplasticity is ejectedfrom the nozzle 61 in a completely melted state by being heated to atemperature higher than or equal to a glass transition point thereof.For example, it is desirable that the ABS resin which has a glasstransition point of about 120° C. is at about 200° C. when dischargedfrom the nozzle 61. A heater may be provided around the nozzle 61 inorder to discharge the shaping material in such a high temperaturestate.

In the three-dimensional shaping apparatus 100, for example, thefollowing metal material may be used as the main material instead of thematerial having thermoplasticity described above. In this case, it isdesirable that components to be melted during the generation of theshaping material is mixed with the powder material made of the followingmetal material and the mixture as the material MR is introduced into theplasticizing portion 30.

Examples of Metal Materials

A single metal of magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr),aluminum (Al), titanium (Ti), copper (Cu), and nickel (Ni), or an alloycontaining one or more of these metals

Examples of the Alloys Described Above

Maraging steel, stainless steel, cobalt chromium molybdenum, titaniumalloy, nickel alloy, aluminum alloy, cobalt alloy, and cobalt chromiumalloy

In the three-dimensional shaping apparatus 100, it is possible to use aceramic material as the main material instead of the metal materialdescribed above. As the ceramic material, for example, oxide ceramicssuch as silicon dioxide, titanium dioxide, aluminum oxide and zirconiumoxide, and non-oxide ceramics such as aluminum nitride can be used. Whenthe metal material or the ceramic material as described above is used asthe main material, the shaping material disposed in the table 210 may becured by sintering.

The powder material of the metal material or the ceramic materialintroduced to the material supply portion 20 as the material MR may be asingle metal powder and an alloy powder, or a mixed material produced bymixing a plurality of types of ceramic material powders. Further, thepowder material of the metal material or the ceramic material may becoated with, for example, a thermoplastic resin as exemplified above, orother thermoplastic resins. In this case, the thermoplastic resin may bemelted to develop fluidity in the plasticizing portion 30.

For example, the following solvent may be added to the powder materialof the metal material or the ceramic material which are introduced tothe material supply portion 20 as the material MR. The solvent can beused by combining 1 type, or 2 or more types selected from thefollowing.

Examples of Solvent

Water, (poly) alkylene glycol monoalkyl ethers such as ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, propylene glycolmonomethyl ether, and propylene glycol monoethyl ether, acetate esterssuch as ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butylacetate, and iso-butyl acetate, aromatic hydrocarbons such as benzene,toluene and xylene, ketones such as methyl ethyl ketone, acetone, methylisobutyl ketone, ethyl n-butyl ketone, diisopropyl ketone andacetylacetone, alcohols such as ethanol, propanol and butanol,tetraalkyl ammonium acetates, sulfoxide solvents such as dimethylsulfoxide and diethyl sulfoxide, pyridine solvents such as pyridine,γ-picoline and 2,6-lutidine, and ionic liquids such as tetraalkylammonium acetate (for example, tetrabutyl ammonium acetate or the like)and butyl carbitol acetate

In addition, for example, the following binder may be added to thepowder material of the metal material or the ceramic material introducedas the material MR into the material supply portion 20.

Examples of Binders

Acrylic resin, epoxy resin, silicone resin, cellulose resin or othersynthetic resin, or PLA (polylactic acid), PA (polyamide), PPS(polyphenylene sulfide), PEEK (polyether ether ketone) or otherthermoplastic resin

B. Other Embodiments

(B-1) The three-dimensional shaping apparatus 100 is not limited to onewhich plasticizes the material by the flat screw 40. For example, thethree-dimensional shaping apparatus 100 may be one which plasticizes thematerial by rotating an in-line screw instead of the flat screw 40.

(B-2) The discharge control mechanism 70 of the embodiment describedabove may be constituted with a valve other than the butterfly valve 72.For example, instead of the butterfly valve 72, a valve such as a ballvalve or a diaphragm valve may be adopted.

(B-3) The three-dimensional shaping apparatus 100 of the embodimentdescribed above may not include the suction portion 75. Even with theconfiguration, by using the discharge control mechanism 70, it ispossible to control the discharge amount so that the discharge amount ofthe shaping material is constant before and after the movement speed ofthe nozzle 61 changes.

(B-4) In the embodiment described above, when the control portion 101controls the discharge control mechanism 70 to stop the discharge of theshaping material from the nozzle 61, the shaping material is sucked bythe suction portion 75 after the butterfly valve 72 is closed. On theother hand, the control portion 101 may perform the suction of theshaping material by the suction portion 75 at a time when the butterflyvalve 72 changes from the open state to the closed state or at the sametime when the butterfly valve 72 closes. That is, the control portion101 may suck the shaping material by the suction portion 75 when thedischarge amount of the shaping material from the nozzle 61 decreases orwhen the discharge of the shaping material from the nozzle 61 isstopped.

(B-5) In the embodiment described above, the gap G between the tip ofthe nozzle 61 and the planned portion MLt in which the shaping materialMM is stacked may be less than the hole diameter Dn at the dischargeport 62 of the nozzle 61. In this case, the shaping material MMdischarged from the discharge port 62 of the nozzle 61 is pressedagainst the planned portion MLt and can be stacked while following awall of the shaping material already disposed at an adjacent position ora wall of the shaping material already disposed at a lower layer. As aresult, since the shaping material is stacked so as to fill void in thevicinity of the planned portion MLt to be stacked, the three-dimensionalshaping object with a low percentage of the void can be obtained andstrength of the three-dimensional shaping object can be improved.

C. Other Aspects

The present disclosure is not limited to each of the embodimentsdescribed above, and can be realized with various aspects in the rangewithout departing from the gist thereof. For example, the presentdisclosure can be implemented as the following aspects. The technicalfeatures in each of the embodiments described above corresponding to thetechnical features in each of aspects described below may be replaced orcombined as appropriate in order to solve part or all of the problemswhich the present disclosure includes or to accomplish part of all ofthe effects which the present disclosure achieves. In addition, unlessthe technical feature is described as essential in the presentdisclosure, the technical feature can be deleted as appropriate.

(1) According to a first aspect of the present disclosure, athree-dimensional shaping apparatus is provided that shapes athree-dimensional shaping object. The three-dimensional shapingapparatus includes a plasticizing portion plasticizing a material togenerate a shaping material, a nozzle having a discharge portdischarging the shaping material toward a table, a movement mechanismchanging a relative position between the nozzle and the table, adischarge control mechanism provided in a flow path which connects theplasticizing portion to the nozzle and controlling a discharge amount ofthe shaping material from the nozzle, and a control portion controllingthe plasticizing portion, the movement mechanism, and the dischargecontrol mechanism to shape the three-dimensional shaping object, inwhich the control portion controls the discharge control mechanism sothat when a relative movement speed between the nozzle and the table isa first speed, the discharge amount of the shaping material is set to afirst discharge amount, and when the relative movement speed between thenozzle and the table is a second speed which is slower than the firstspeed, the discharge amount of the shaping material is set to a seconddischarge amount which is smaller than the first discharge amount.

In such a three-dimensional shaping apparatus of the aspect, when therelative movement speed between the nozzle and the table is high, thedischarge amount of the shaping material is large, and when the relativemovement speed is slow, the discharge amount of the shaping material issmall, so that the shaping precision of the three-dimensional shapingobject can be improved.

(2) In the three-dimensional shaping apparatus of the aspect, thecontrol portion may use the discharge control mechanism to control thedischarge amount so that the discharge amount of the shaping materialper unit volume in the three-dimensional shaping object is constantbefore and after the relative movement speed between the nozzle and thetable changes. In such a three-dimensional shaping apparatus of theaspect, since the discharge amount of the shaping material per unitvolume in the three-dimensional shaping object is constant before andafter the relative movement speed between the nozzle and the tablechanges, the shaping precision of the three-dimensional shaping objectcan be improved.

(3) In the three-dimensional shaping apparatus of the aspect, thedischarge control mechanism may include a butterfly valve which changesan opening degree of the flow path by rotation thereof in the flow path,and the control portion controls the discharge amount by adjusting arotation angle of the butterfly valve according to the relative movementspeed between the nozzle and the table. In such a three-dimensionalshaping apparatus of the aspect, the discharge amount of the shapingmaterial can be adjusted by a simple configuration.

(4) In the three-dimensional shaping apparatus of the aspect, there maybe provided a suction portion connected to the flow path between thedischarge control mechanism and the discharge port in the flow path andsuctioning and temporarily reserving the shaping material in the flowpath, in which the control portion may cause the suction portion toperform suction of the shaping material when discharge of the shapingmaterial from the nozzle is stopped by controlling the discharge controlmechanism. In such a three-dimensional shaping apparatus of the aspect,when the discharge of the shaping material from the nozzle is stopped,it is possible to suppress the trailing of the shaping material from thenozzle.

(5) In the three-dimensional shaping apparatus of the aspect, thecontrol portion may start movement of the nozzle after a part of theshaping material reserved in the suction portion is sent from thesuction portion to the flow path to be discharged from the nozzle whenthe discharge of the shaping material from the nozzle is started,control the discharge control mechanism to start supplying the shapingmaterial from the plasticizing portion to the nozzle, and send theremaining shaping material reserved in the suction portion from thesuction portion to the flow path. In such a three-dimensional shapingapparatus of the aspect, it is possible to discharge the shapingmaterial using the suction portion so as to compensate for theresponsiveness of the discharge control mechanism, so that shaping speedof the three-dimensional shaping object can be improved.

(6) In the three-dimensional shaping apparatus of the aspect, thecontrol portion may determine that the discharge of the shaping materialis to be stopped from the nozzle when the position of the nozzlerelative to the table is determined to be at a vicinity of a path fordischarging the shaping material. In such a three-dimensional shapingapparatus of the aspect, it is possible to stop the discharge of theshaping material with good timing even when responsiveness of thedischarge control mechanism is low.

(7) In the three-dimensional shaping apparatus of the aspect, theplasticizing portion may include a flat screw having a grooved surfaceon which a groove portion is formed and a barrel including a facingsurface facing the grooved surface of the flat screw, a communicationhole formed on the facing surface, and a heater, and the plasticizingportion may generate the shaping material by melting at least a part ofthe material by rotation of the flat screw and heating by the heater andcause the shaping material to flow out of the communication hole. Insuch an aspect, the three-dimensional shaping apparatus can beminiaturized.

(8) According to a second aspect of the present disclosure, a method ofmanufacturing a three-dimensional shaping object is provided. The methodof manufacturing includes generating a shaping material by plasticizinga material by a plasticizing portion and discharging the shapingmaterial from a nozzle towards a table while changing a relativeposition of the nozzle and the table, in which a discharge controlmechanism which is provided in a flow path connecting the plasticizingportion to the nozzle and controls a discharge amount of the shapingmaterial from the nozzle is controlled so that when a relative movementspeed between the nozzle and the table is a first speed, the dischargeamount of the shaping material is set to a first discharge amount, andwhen the relative movement speed between the nozzle and the table is asecond speed which is slower than the first speed, the discharge amountof the shaping material is set to a second discharge amount which issmaller than the first discharge amount.

In such a method of manufacturing the three-dimensional shaping objectof the aspect, when the relative movement speed between the nozzle andthe table is high, the discharge amount of the shaping material islarge, and when the relative movement speed is slow, the dischargeamount of the shaping material is small, so that the shaping precisionof the three-dimensional shaping object can be improved.

The present disclosure is not limited to the method of manufacturing thethree-dimensional shaping apparatus described above or thethree-dimensional shaping object, and can be realized in various forms.For example, it can be realized in the form of a method of controllingthe three-dimensional shaping apparatus, a three-dimensional shapingmethod, a computer program for shaping the three-dimensional shapingobject, a non-transitory recording medium which records the computerprogram, or the like.

What is claimed is:
 1. A three-dimensional shaping apparatus shaping athree-dimensional shaping object, comprising: a plasticizing memberconfigured to plasticize a material to generate a shaping material; anozzle having a discharge port discharging the shaping material toward atable; a movement mechanism changing a relative position between thenozzle and the table; a discharge control mechanism configured to changean opening degree of a flow path which guides the shaping material tothe discharge port to control a discharge amount of the shaping materialfrom the discharge port; a storage device configured to store a program;and a processor configured to execute the program so as to: change arelative position of the nozzle and the table at a first speed todischarge the shaping material toward the table; set the opening degreeto a first degree to discharge a first discharge amount of the shapingmaterial from the discharge port when the relative position of thenozzle and the table is changed at the first speed; change the relativeposition of the nozzle and the table at a second speed to discharge theshaping material toward the table; and set the opening degree to asecond degree to discharge a second discharge amount of the shapingmaterial from the discharge port when the relative position of thenozzle and the table is changed at the second speed, wherein the secondspeed is slower than the first speed, and the second discharge amount issmaller than the first discharge amount.
 2. The three-dimensionalshaping apparatus according to claim 1, wherein the processor isconfigured to control the discharge control mechanism to adjust adischarge amount of the shaping material per unit volume in thethree-dimensional shaping object to be constant during the relativeposition of the nozzle and the table changes is changed at the first andsecond speeds.
 3. The three-dimensional shaping apparatus according toclaim 1, further comprising: a suction member connected to the flow pathbetween the discharge control mechanism and the discharge port in theflow path, the suction member being configured to suck the shapingmaterial into a branched path from the flow path and reserve the suckedshaping material in the branched path, wherein the processor isconfigured to cause the suction member to suck the shaping material whendischarge of the shaping material from the discharge port is stopped bycontrolling the discharge control mechanism.
 4. The three-dimensionalshaping apparatus according to claim 3, wherein the processor isconfigured to control the suction member to eject a part of the reservedshaping material in the suction member to the flow path when theprocessor causes the nozzle to start discharging the shaping material,after the suction member ejects the part of the reserved shapingmaterial in the suction member to the flow path, the processor isconfigured to: change the relative position of the nozzle and the table;start supplying the shaping material from the plasticizing member towardthe discharge port via the flow path by controlling the dischargecontrol mechanism; and eject a remaining of the reserved shapingmaterial in the suction member to the flow path.
 5. Thethree-dimensional shaping apparatus according to claim 1, wherein theplasticizing member includes a flat screw and a barrel, the flat screwhas a grooved surface on which a groove is formed, the barrel includes afacing surface facing the grooved surface of the flat screw, acommunication hole formed on the facing surface, and a heater, and theplasticizing member is configured to generate the shaping material bymelting at least a part of the material by rotation of the flat screwand heating by the heater and cause the shaping material to flow out ofthe communication hole to the flow path.
 6. A method of manufacturing athree-dimensional shaping object, comprising: plasticizing a material togenerate a shaping material; discharging the shaping material from adischarge port of a nozzle towards a table via a flow path upstream ofthe discharge port in a shaping material flow direction while changing arelative position of the nozzle and the table to form thethree-dimensional shaping object; and executing a program stored in amemory by a processor so as to: control a discharge control mechanismconfigured to change an opening degree of the flow path to change adischarge amount of the shaping material from the discharge port; changea relative position of the nozzle and the table at a first speed todischarge the shaping material toward the table; set the opening degreeto a first degree to discharge a first discharge amount of the shapingmaterial from the discharge port when the relative position of thenozzle and the table is changed at the first speed; change the relativeposition of the nozzle and the table at a second speed to discharge theshaping material toward the table; and set the opening degree to asecond degree to discharge a second discharge amount of the shapingmaterial from the discharge port when the relative position of thenozzle and the table is changed at the second speed, wherein the secondspeed is slower than the first speed, and the second discharge amount issmaller than the first discharge amount.